Anisotropic compressive behavior of extruded Mg alloy plates with different width-thickness ratios

Investigation of the microstructural characteristics and compressive properties of extruded AZ31 alloy plates with width-thickness ratios (w/t ratios) of 1, 2, and 3 revealed that a higher ratio promotes dynamic recrystallization (DRX) behavior during hot extrusion. This leads to a decrease in both the fraction of non-DRXed grains and the average grain size. Extruded alloy with a w/t ratio of 1 exhibits a ring basal fiber texture that is homogeneously distributed over its entire cross-sectional area, resulting in identical stress-strain behavior under compression along the normal direction (ND) and transverse direction (TD). In contrast, significant anisotropy appears between the compressive behavior along the ND and TD in alloys with w/t ratios of 2 and 3, which is attributed to a difference in the active dominant deformation mechanism (i.e., slip for the ND and twinning for the TD) caused by the strong ND-oriented basal texture. Consequently, the compressive yield strength is up to ~2.25 times higher along the ND than along the TD.